Flashlights of various sizes and shapes are well known in the art. Many use two or more dry cell batteries arranged in a housing as a source of electrical energy.
Battery technology is such that as electrical power is withdrawn from the battery cell, the voltage available across a given current load will decrease. In the case of a flashlight, this decrease of available voltage across the load causes reduced light output, gradually dimming the light as the battery charge depletes.
To prolong battery life, light emitting diodes (LEDs) are becoming more common as light sources for handheld flashlights, especially miniature flashlights. There are other advantages to using LEDs as opposed to other light sources in handheld flashlights. For example, LED bulbs are more durable, longer lasting and energy efficient than incandescent light bulbs. In contrast to regular incandescent bulbs, LEDs do not have a filament. Incandescent bulbs rely on filaments for conducting current that results in light being emitted from the bulbs. These filaments are easily broken or burned out, which requires bulb replacement quite frequently.
Most importantly, LEDs are extremely efficient. They have a battery life that is 10 to 15 times that of regular incandescent lights and consume less than 10% of the energy of an incandescent lamp. As such, the need to replace the batteries in an LED flashlight as opposed to an incandescent bulb flashlight is much less.
The energy emitted by an LED is related to the electrical charge q of an electron and the voltage V required to light the LED by the expression: E=qV. By substituting known values for q and V into this equation, it is apparent that LEDs require very little energy to emit light, thus minimizing the need to replace batteries as frequently. Because the energy requirements for LEDs are so low, many developers of LED flashlights utilize very low voltage battery cells which are small in size but hold an adequate charge for driving an LED to emit light for many hours. Thus, the present invention seeks to minimize the need for battery replacement even more by providing a flashlight that utilizes a larger battery having a higher voltage to further minimize the need for replacement in LED flashlights.